Open AccessDynamic variation of the microbial community structure during the long‐time mono‐fermentation of maize and sugar beet silage
Author(s) -
Klang Johanna,
Theuerl Susanne,
Szewzyk Ulrich,
Huth Markus,
Tölle Rainer,
Klocke Michael
Publication year - 2015
Publication title -
microbial biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.287
H-Index - 74
ISSN - 1751-7915
DOI - 10.1111/1751-7915.12263
Subject(s) - terminal restriction fragment length polymorphism , silage , sugar beet , methanosaeta , biology , food science , fermentation , microbial population biology , sugar , agronomy , microbiology and biotechnology , bacteria , biochemistry , restriction fragment length polymorphism , polymerase chain reaction , genetics , gene
Summary This study investigated the development of the microbial community during a long‐term (337 days) anaerobic digestion of maize and sugar beet silage, two feedstocks that significantly differ in their chemical composition. For the characterization of the microbial dynamics, the community profiling method terminal restriction fragment length polymorphism ( TRFLP ) in combination with a cloning‐sequencing approach was applied. Our results revealed a specific adaptation of the microbial community to the supplied feedstocks. Based on the high amount of complex compounds, the anaerobic conversion rate of maize silage was slightly lower compared with the sugar beet silage. It was demonstrated that members from the phylum B acteroidetes are mainly involved in the degradation of low molecular weight substances such as sugar, ethanol and acetate, the main compounds of the sugar beet silage. It was further shown that species of the genus M ethanosaeta are highly sensitive against sudden stress situations such as a strong decrease in the ammonium nitrogen ( NH 4 + ‐ N ) concentration or a drop of the pH value. In both cases, a functional compensation by members of the genera M ethanoculleus and/or M ethanosarcina was detected. However, the overall biomass conversion of both feedstocks proceeded efficiently as a steady state between acid production and consumption was recorded, which further resulted in an equal biogas yield.